Thread: Ryobi Linisher Overhaul

I have acquired a 1990 Ryobi 100 x 150 mm (4" x 6") benchtop linisher. The usual type with a disk and a belt, adjustable horizontal to vertical. The frame is heavy cast iron.


It fell into my hands when a fellow railway builder discarded it because of a 'collapsed tail drum bearing'. He had used it since new in the building of a series of 2-1/2", 3-1/2", 5" and 7-1/4" locomotives. His solution was to purchase a new Ryobi one.

It 'looked' repairable, I cannot resist a bargain (free), so home it went.

It turned into a major job to dismantle it. Impossible access provisions, a Heath Robinson design and problems discovered as each layer was removed.

I test ran it before starting - what a cacophony, its a wonder my mate could still use it at all !

The score so far:
- motor bearings,
- head spindle re-machine and fit bush to the disk,
- head spindle ball bearings,
- tail spindle new shaft,
- tail drum new sleeve bearings,
- several circlips.

The photo shows the initiating cause, with the offending sleeve bearing already bored out.
The spindle is retained (sort of) in the arm and the tail drum rotates on two sleeve bearings.
The spindle diameter is 12 mm and the wear is about 0.7 mm on one side.

My plan is to make a new spindle and fit new sleeves.
Suggestions please on the materials for the tail drum spindle and bearings.
P1020071 Compr.jpg

John

Hi John, if it were me, I'd fit proper bearings to the drum, and make a shaft to suit. That way, it should outlast the rest of the machine.
I was at a friends place the other day, he showed me his linisher, the motor had died, so instead of scrapping it, someone dismantled it, removed the offending motor, cut a hole in the back to allow for a belt, and re-assembled it with a washing machine motor to power it. Can get a pic of it, if required.
Kryn

Originally Posted by electrosteam

. . . .It turned into a major job to dismantle it. Impossible access provisions, a Heath Robinson design and problems discovered as each layer was removed.

I agree, they are a dreadful design.
I've delved inside the one at the mens shed a couple of times and they are prig of a machine to get into.

I test ran it before starting - what a cacophony, its a wonder my mate could still use it at all !

Don't hold your breath when you fix the bearing - they are a very noisy machine even with functional bearings and because of this I think carefully before having one in my shed.
BTW, the dust collection is almost useless.
Amongst other problems, the overly complex switch on the mens shed unit failed and a replacement switch was going to cost ~$50 so the (very experienced) shed sparky and I spent many hours trying to replace it with another switch but because of the unusual circuit it was wired into we weren't able to get it working properly. In the end the shed committee bought a completely new replacement from bunnings for just $149 .

If you own a lathe.

Perhaps it might be easy to grab a grade 8 bolt of suitable size.

It will be better material than the original.

The bolts machine up nice as well.

Grahame

Originally Posted by BobL

Amongst other problems, the overly complex switch on the mens shed unit failed and a replacement switch was going to cost ~$50 so the (very experienced) shed sparky and I spent many hours trying to replace it with another switch but because of the unusual circuit it was wired into we weren't able to get it working properly..

And that is designed that way and NOT by accident.

Grahame

Discussed with an expert machinist friend, we decided on 12 mm ground 4140 for the shaft.
As it seemed doubtful that oilite bushes would be conveniently available, we decided on phosphor bronze reamed 12 mm.
Will include the shaft bearing grooves and relieved central section to hold some oil.

I should (or someone else should) get another 25 years out of it !
Further posts will follow from mid-January.
Enjoy the Season,
John.

A success, a mishap and a question.

Success - new bearings in the motor and it runs sweetly.

Mishap - fitted a 6001zz bearing to the drive end of the head drum shaft. I assisted my mate and I thought we did a good, careful job. BUT, test spins showed bad clunky operation. On reflection, we could have adopted a better press sequence. The fits are minimal and the forces very low. Discussed with the supplier who generously exchanged it at no coast. Fitted the new bearing and it runs fine.

Question - the terminating failure was severe erosion of the tail drum shaft and bearing. The shaft is fixed by the steering adjustment bolt. Having the shaft fixed with a sleeve bearing seems wrong to me. Do similar linishers have the tail end drum shaft fixed with sleeve bearings ?

Ordered a length of ground 12 mm 4140 on ebay, advised yesterday that it had been delivered - no sign of it so far.

The head drum is complete:
- drum is located with a grub screw,
- table rotating support member has new bearing,
- drive pulley has thread locker onto splined shaft,
- disc mounting shaft end has a two-step sleeve epoxied on (internal step to short length of spline, outer step to support disc), cleaned up true in lathe,
- disc bored out to suit sleeve with two additional M5 grub screws.
If anything goes wrong, it will be a devil to dismantle !

Intention was to mount between centres on lathe and clean up the disc.
Testing shows minimal run-out so left as is.
But, disc has to be removed to mount onto table, so we shall see.
P1020075 Compr.jpg
John.

The errant 4140 bar is still missing.

Started thinking about Kryn’s suggestion in Post #2 for Tail Drum rolling element bearings.

The drum end is shown in the photo, essentially hollow die-cast cylinder dia 60 mm, barrel shape +0.5 mm and length 105 mm.

First trial drawing is also shown of a possible arrangement using 6001 zz ball bearings.

The most difficult aspect is holding the drum to achieve the necessary internal rebate machining.
At the moment, the most practical approach is to simply use the 4-jaw in the lathe.
The jaws provide 25 mm of contact versus the drum 105 mm length.

The drum is very square to the ends, and when in the 4-jaw, the air-gap close to the chuck body due to the barrel shape is easily checked as uniform.
The risk is bruising of the drum, or worse, crushing in, especially if the drum end close to the body moves to close the air-gap.

An obvious approach is to wrap the drum end with a suitable shim.
Measurement has the drum end 0.37 mm smaller than the diameter at the chuck jaw contact point.

Can anyone suggest a better way to hold the drum for machining ?

Tail Drum Compr.jpgRyobi Linisher Tail Drum Bearing 1.jpg

John.

Thick card, like a business card, will both cushion and take care of irregularities. A fixed steady at the other end (if you can get it there) will also better support the end being bored

If you have a mill and boring head, it may be better doing it that way. If you had access to Al welding facilities it may even be better to make from a piece of tube with some turned end pieces. Thin die castings like that are troublesome as they can have voids or defects hiding in them.

Michael

Originally Posted by Michael G

Thick card, like a business card, will both cushion and take care of irregularities. A fixed steady at the other end (if you can get it there) will also better support the end being bored

If you have a mill and boring head, it may be better doing it that way. If you had access to Al welding facilities it may even be better to make from a piece of tube with some turned end pieces. Thin die castings like that are troublesome as they can have voids or defects hiding in them.

Michael

Hi John,

I agree with Michael, a steady at the far end and then turn the inside of the tube enough to true it up, then make a pair of alloy bushes to fit. Turn the alloy bushes to suit your bearings. fit the bearings and then loctite the bushes in place.

Following all the good advice, the tail drum was held in the 4-jaw with 0.003" shim wrapped at the chuck body end.
Trued up, then supported by a fixed steady for the machining of the ends to accept bearing support plugs.
Got some rub marks from the steady fingers, but I figure no problem to a linisher belt.
The bearing support plugs are 2011 T6 aluminium machined a free sliding fit to the drum with roughed-out bearing registers.

Plan is to J-B Weld epoxy glue the plugs in position, then machine the bearing registers using the 4-jaw and fixed steady.

I have a 6001 DD rubber seal bearing, are these suitable for the tail drum ?
I believe this type of seal will hold the bearing internal grease better than metal dust seals in this application.

Once the tail drum is finished, I will measure the distance between the bearing registers and machine the shaft from bright MS with bearing shoulders 0.2 mm greater.
Assembly again has a certain degree of non-reversability, but there does not appear to be any attractive alternative.

Hi Electrosteam,

It doesn't really matter whether you use shoulders on the inside or circlips on the outside on the shaft ! Either way the bearings only need to be a good finger push fit onto the shaft.

Those bearing support plugs look very nice too.

Linisher is operational, outstanding is a guard for the drive belt.
The original guard is just too complicated/difficult to re-use.

Tally:
- new motor bearings,
- machined drive drum shaft to accept bush for the disk,
- disk bush,
- disk bored to suit bush and two grub screws added,
- new drive drum bearings,
- tail drum re-designed for ball bearings,
- tail drum machined,
- two tail drum end plugs,
- new tail drum shaft to suit new ball bearing arrangement,
- new tail drum ball bearings.

Belt direction was initially a puzzle (compared with my pedestal linisher), then the penny dropped.
Noise is low, mainly a rattle from the tension adjustment assembly.

Photos show the tail drum shaft and final assembly.
Ryobi Linisher Tail Shaft compr.JPGRyobi Linisher Assembled compr.JPG

John

Thanks for the "How it was done, WIP" report, I know someone who picked up one the same at a garage sale. Will probably get the job of repairing it, when it decides to drop a clanger.
Nice to see a little machine resurrected instead of dumped.
Kryn